The present invention relates to an apparatus for melt spinning and cooling a group of filaments.
When synthetic threads are melt-spun from a polymer melt using a spinneret with a plurality of nozzle bores, a plurality of strand-like filaments is extruded. The filament strands coming out of the spinnerets must be cooled before being taken up in the form of threads or thread bundles after further treatment. The cooling agent used is preferably air, which flows perpendicularly to the thread direction and is trained onto the filaments. The cooling air can penetrate the group of filaments from the exterior toward the interior or from the interior toward the exterior. German Laid Open Publication DE 36 29 731 A1, for example, discloses a prior-art device in which the cooling air stream penetrates a group of filaments from the interior toward the exterior as disclosed.
In the prior-art device the group of filaments is produced by an annular spinneret of a spinning device. A cooling device is provided below the spinning device and comprises a coolant dispersing head that is substantially centered relative to the spinneret. This coolant dispersing head is connected with a holder through which a cooling medium is introduced into the interior of the coolant dispersing head. The coolant dispersing head has a porous shell that is made, for instance, of a sintered material, such that the cooling air flowing into the interior of the coolant dispersing head exits radially therefrom and permeates the group of filaments. In this type of device, the coolant dispersing head can be displaced between an operating position and a standby position to permit startup of spinning the group of filaments at the beginning of the process. In standby position, the coolant dispersing head is guided completely out of the spinning area at a distance from the spinneret, such that particularly prolonged downtimes are inevitable if the process is interrupted. To enable the coolant dispersing head to be guided into its operating position after spinning startup, a strong radial air stream is produced at the free end of the coolant dispersing head by means of an additional annular gap that is formed at the end of the coolant dispersing head. Particularly when the coolant dispersing head is swiveled, a problem occurs wherein the filament strands that are blown away by the coolant dispersing head stick together. Another drawback is that an additional air stream must be guided to the annular gap by additional guiding means within the cooling dispersing head. When the operating position is reached, this additional air stream must be shut off by additional means.
Thus, there is a need in the art to equip an apparatus of the initially described type with a flexible cooling device, which enables the coolant dispersing head to be rapidly brought into its operating position after spinning startup without an additional supply of air.